Pony considers Tim Shepard and his gang “future convicts” because they are more organized.
Pony feels that he, Darry, Two-Bit, and Soda should not spend too much time around Tim Shepherd and his gang and the leader of the Brumly boys because they are too rough.
We're greasers, but not hoods, and we don't belong with this bunch of future convicts. We could end up like them, I thought. We could. And the thought didn't help my headache. (Ch. 9)
Pony just wants to be make a distinction between the tough greasers and the ones that are just trying to make it in their neighborhood. He points out that everyone has to be in a gang, and being in a gang is about survival. Although some boys like Dally do enjoy messing around sometimes, and getting in trouble with the law, for most of them they are just targets because of who they are and where they live.
When you're a gang, you stick up for the members. If you don't stick up for them, stick together, make like brothers, it isn't a gang any more. It's a pack. (Ch. 2)
Being in a gang is about survival for the greasers, not about fun.
The Shephard gang, on the other hand, is serious and organized. Pony’s gang doesn’t even really have a leader. They are just a bunch of guys that are from the same neighborhood and stick up for each other. Although they might get into trouble, they avoid weapons and serious crimes.
The greasers are targeted by the Socs because they are greasers. They get jumped if one of them is walking alone. When one gets in a fight, the others have to fight a rumble against the rival gang in order to stick up for him. The cycle of violence always continues this way, until no one knows or cares how it started.
This is Ponyboy's world. There is no logic or organization to it. Yet with some gangs, there is order to the chaos. He realizes that this is not necessarily better. He does not want to be a better gang member.